Who new that Dr. Sheldon Cooper has just a little bit of a conscience? It's five years into
"The Big Bang Theory" and it looks like we're learning more and more about the genius every day.

[Spoiler Alert]

After years of sponging off of her neighbors, Penny (
Kaley Cuoco) decides to do a nice thing and get Sheldon (
Jim Parsons) and Leonard (
Johnny Galecki) a present they'll each appreciate - a classic
"Star Trek" transporter room toy.

Being the geeks they are, they refuse to open the gifts as it would immediately devalue them. But curiosity gets the better of Sheldon after "Action Figure Spock," voiced by
Leonard Nimoy, tells him in a dream that it would be illogical to not play with his present. This goes well until the transporter quickly breaks. Sheldon is now faced with the conundrum of what to do next.

He quickly decides to swap the toy with the identical version that Leonard has. But in a scene reminiscent of
Edgar Allen Poe's "The Tell-Tale Heart," we soon find out that the pressure may be too much for even Sheldon to handle.

In the other storyline, the unlucky-in-love Raj (
Kunal Nayyar) enlists his parents help in finding him a mate. This goes perfectly until we find out that Raj and his date may not exactly see eye-to-eye on a few things - most notably which "team" they're playing for. But in the end Raj finds the perfect partner, and she's adorable.

In the spirit of Nimoy's guest starring role, rather than assigning a rating on Thursday's (March 29) episode, we'll just say it should "live long and prosper."